How Will NextGen Improve Your Life?

We’ve all heard about “NextGen” air traffic control, but besides the generic guarantee of shorter delays, do we really know what it will do for us? Sometimes the benefits to the traveler aren’t really all that clear, and that’s probably because the actual definition is more of a nebulous catch-all for change than anything else.

Today, I’m going to talk about Required Navigation Performance (RNP), a form of Performance-based Navigation (PBN), and what it can do to help airport arrivals. But instead of defining it in boring terms, I’ll look at a recent implementation high in the Andes to show how you can benefit from it.

RNP allows airplanes to fly precise, complex approaches without the need for any ground-based navigational aids. Today, the use of Instrument Landing Systems (ILS) hampers the ability to run complex approaches in some areas, because difficult terrain prevents these ground-based systems from adequately guiding the aircraft. Consequently, when visibility is bad, some of these airports see serious constraints.

One of those places is Cusco, Peru. Here is a picture I took looking east after landing there last year:

It may not look like much, but consider this. That runway is about 11,000 ft above sea level. It sits in a dead-end valley with only way good way out. As you can see, those mountains go up pretty quickly. And by the way, this view is actually of the GOOD way out of the valley.

Airplanes fly in from the west, descend into the valley, and then do a sharp loop to land back toward the west. It was a fairly dramatic arrival for us, though the clear blue skies made it seem routine. Combine that complexity with gusty winds and fog or rain and you’ve got one incredibly tricky arrival.

In fact, it’s so tricky that you’ll never experience it. When the weather gets bad, flights get canceled. Until now. LAN Peru, the largest operator at the airport, recently finished testing a system from Naverus that allows it to fly an RNP approach into the airport.

The added precision of the RNP approach allows LAN to fly with more accuracy on a very complicated approach, and that means they can land safely in lower visibility situations.

This isn’t a new thing. Alaska, for example, first tested RNP flying into San Francisco several years ago. When the fog rolls in, SFO has to spread out its arrivals because the two runways are too close for comfort using existing systems. Just imagine if SFO could actually operate at normal capacity during foggy days thanks to more precise approaches. Delays would disappear from the airport.

This is just a glimpse of the future. There are other systems that can have similar results, and of course there are other pieces of NextGen that impact other phases of flight. When you hear buzzwords about NextGen and RNP, this is the type of thing that will eventually be possible. If you’d like to learn more, take a listen to this podcast on the subject. (It’s a little dry, but the information is good.)

10 Responses to How Will NextGen Improve Your Life?

Yes, I am sure that RNP will work great when all equipment works as expected… but what happens when equipment fails? Should (under NextGen) a plane divert to the nearest airport when its RNP (or transponder) is out of order? What impact will that have on delays?

Amazing how submarines can travel underwater anywhere in the world using ‘machines’ as eyes, but airplanes haven’t mastered landing in any weather condition without having to slow down using human eyes. When the computer hit the cockpit, this area should have seen a turn around sooner.

The assumption is that NextGen will allow airlines to operate their current schedules closer to normal in adverse visibility situations. It does not appear to address wind shear, micro-bursts or lightning on the field and therefore does not serve as a fix-all for every kind of weather.

Secondly, another assumption is that airlines will continue to operate current schedules with NextGen navigation installed. Doubtful.

If NextGen increases operational efficiency at key airports I see many a scheduler drooling at greater fleet optimization opportunities by increasing flying at those locations. That will push NextGen to its limits, elicit screams of false advertising from the airlines who increased their lift and cries of foul from customers who will feel nothing has changed at all except the increase in competition for the overnight cots.

Bottom line seems to be that NextGen needs to be carefully positioned in the public’s mind for what it can do and what it can do nothing about. Otherwise it will be seen as a false prophet intended to fix delays but leaves masses of people cooling their heels because of a rainy night in Georgia.

Queenstown in NZ has had RNP equipment for a while now. It too is an airport in a narrow mountain basin with a twisting approach over mountain pass and hills.

RNP has had a huge effect – Air New Zealand has RNP on enough aircraft that it has a decent ontime performance (though still not as good as airports out of the mountains – even RNP can’t help if the airport is clouded in badly or snowed in). Whereas Qantas did not have RNP on their domestic aircraft and had a terrible cancellation rate and ontime performance. One winter I analysed their stats and it was about a third cancelled flights and a significant number not cancelled but diverted – if you actually landed at Queenstown you were lucky.

MathFox – These are all the procedures that they’ll need to fully develop, I imagine. But I would expect that if RNP isn’t functioning for one reason or another, they’ll revert to a backup system, just as they do today if the ILS is down for some reason at an airport. And if that backup system doesn’t allow for such precise approaches, then they’ll likely have to divert.

Optimist – Nothing can address problems with microbursts, windshear, etc. If those are around, no amount of technology will make them safe to fly through. You just have to wait for them to go away or, if it’s not right over the airport, go around them. But NextGen systems should make it easier for aircraft to fly around weather if it enables free flight. Then airplanes would have more latitude to go as they please.

Of course, the biggest constraint is the runway at the airport. There are only so many planes you can land on each runway in a given period of time. At SFO, bad weather now reduces that number significantly so NextGen can help relieve that. But at many airports, the gains will still be only slightly incremental, and the only solution will be more runways.

CF, I think you’re overstating the possible benefits of RNP, particularly regarding delay reduction at SFO. While it will help increase arrival rates/reduce delays during low ceiling/visibility conditions, I don’t think that by itself RNP is going to come close to maintaining normal VFR capacity in poor weather. Maybe that can happen in the long term when RNP will be used in combination with other nextgen technologies, but I think that to say “delays would disappear from the airport” just because of RNP sounds a little pie-in-the-sky.

atomsareenough – I was purposefully ambiguous when I was talking about SFO, because I wasn’t quite sure what exactly would be necessary to make it a reality. That’s why I said, “Just imagine if SFO could actually operate at normal capacity during foggy days thanks to more precise approaches. Delays would disappear from the airport.”

More precise approaches combined with policy changes should allow for it to be a reality, but I don’t know exactly what technology is required for the FAA to decide that it would be safe. Do you know?

The Global Traveller is right on in his comments about Queenstown, and the role of Air New Zealand. The airline was also the first foreign carrier and second carrier overall (following Alaska Airlines) to use advanced technology approaching SFO, including “tailored approach” at SFO and LAX. Air NZ is also planning to use RNP to improve traffic efficiency at the three main NZ airports, AKL, WGN and CHC.

CF – I know you weren’t making any overt claims, but even your “just imagine” scenario seems like wishful thinking if you are just talking about RNP. I don’t think you can get to the point where SFO operates at full capacity on foggy days least until there is full implementation of other technologies as well, like perhaps a full ADS-B system and cockpit traffic displays (something like CDTI), which can enable pilots to “see” other aircraft with enough accuracy built into them to really reduce separation minimums.

atomsareenough – You’re right – it IS wishful thinking! Certainly all aircraft flying into the airport would need to be equipped with RNP capabilities for this to work at the very least, so it’s not going to happen soon. (The benefits in Cusco, however, could be realized if only one aircraft has it.)